1. Field of the Invention
The present invention relates generally to a noise reducing cover for moving parts of an internal combustion engine, as in a cylinder head cover, oil pan or the like, and more specifically to a noise reducing cover for moving parts of an internal combustion engine comprising a plurality of layers of vibration and sound absorbing material for reducing the noise of the internal combustion engine moving parts.
2. Description of the Prior Art
Covers for moving parts of internal combustion engines, as in cylinder head covers (valve covers), oil pans, valley covers, valve lifter covers, and the like have traditionally been formed from sheet metal. Solid sheet metal is hardly a vibration or sound absorbing material; in fact, solid metal is one of the best sound and vibration conductors known to man. When a cylinder head cover or the like is rigidly mount to an internal combustion engine, which of course, it must be in order to perform its intended function, the cover itself becomes an excellent conductor of noise and vibration produced by the internal combustion engine. In fact, due to the shape of certain types of such covers having large, essentially flat sections, these covers become excellent amplifiers of engine noise. Additionally, engine vibration is transmitted to the particular cover, thus creating another source of noise-the vibration of the cover itself.